Chemical composition of banana rachis from three varieties (Grande naine, Pelipita, and CRBP969) was ana- lyzed, and the genotype contribution to composition variabil- ity was investigated. Wet chemistry and instrumental analysis procedures (X-ray diffraction, 31P NMR spectroscopy, and thermogravimetry) were used. Some significant differences were found among the three genotypes: GN-AAA genotype was found to be significantly the highest in ash fraction (30.16 %) and the lowest in acid insoluble lignin (6.58 %) at 95 % confidence level. It showed also the highest content in potassium (43.5 % in ash). Implication of compositional dif- ferences on valorization efficiency by biochemical or thermo- chemical pathways was investigated. For this purpose, corre- lation coefficients between compositional characteristics and yields in volatile compounds from pyrolysis and glucose yields from enzymatic saccharification were analyzed. Ash content was revealed to be the main drawback parameter for volatile yields from pyrolysis (r = −0.93), while for glucose yields during saccharification were limited mainly by the con- tent in guaiacyl units of the lignin fraction (r = −0.98). How- ever, a strong and positive correlation was established be- tween the volatiles yield and the acid insoluble lignin content (r = 0.98) Thus, according to these observations and based on their compositional significant differences, GN-AAA was the better candidate for bioconversion pathway while PPT-ABB and CRBP969-AAAB samples were shown to be better can- didates for thermochemical conversion pathway. This work gives important preliminary information for considering ba- nana rachis as an interesting feedstock candidate for biorefinery. [less ▲]

It is well known that chemical pesticides have harmful effects on human health and environment. In this context, the interest for alternative products such as biopesticides is increasing. Among them ... [more ▼]

It is well known that chemical pesticides have harmful effects on human health and environment. In this context, the interest for alternative products such as biopesticides is increasing. Among them, elicitors act on the plants by inducing systemic resistance against diseases caused by fungal, viral, bacterial agents and insects. Rhamnolipids are surface active molecules produced mainly by various strains of the bacterium Pseudomonas aeruginosa. These secondary metabolites are composed of one to three fatty acids with various chain lengths linked through a glycosidic bond to one or two rhamnose moieties. The fatty acids are linked together through an ester bond. These molecules have shown several biological activities including plant defense stimulation. It has been suggested that this elicitor activity could be related to an interaction of rhamnolipids with the lipid bilayer of the plant plasma membrane (PPM) and lead to its destabilization, which can activate the plant defense signaling pathways. In this context, interactions of two rhamnolipids (Rha-C10-C10 and Rha-Rha-C10-C10) with biomimetic membranes of PPM such as Langmuir monolayers and multilayers were investigated using biophysical and in silico approaches. [less ▲]

In Cameroon , the ratio of energy cost to standard of living for both electric and fuel energy is higher than in USA and EU. The local energy needs could be met by valorizing local wastes in an ... [more ▼]

In Cameroon , the ratio of energy cost to standard of living for both electric and fuel energy is higher than in USA and EU. The local energy needs could be met by valorizing local wastes in an environmentally and economically sustainable way. Banana and plantain plants produce significant quantities of post-harvest biomass wastes such as bulbs, pseudo stems, leaf sheaths, petioles–midribs, leaf blades, peduncles, rachis and blossoms which can be converted to methane-rich biogas by anaerobic digestion (AD). AD is a natural process of degradation of organic materials. [less ▲]

Rhamnolipids are surface active molecules produced mainly by various strains of the bacterium Pseudomonas aeruginosa. These secondary metabolites are composed of one to three fatty acids with various ... [more ▼]

Rhamnolipids are surface active molecules produced mainly by various strains of the bacterium Pseudomonas aeruginosa. These secondary metabolites are composed of one to three fatty acids with various chain lengths linked through a glycosidic bond to one or two rhamnose moieties. The fatty acids are linked together through an ester bond. These molecules have shown several biological activities including plant defense stimulation. It has be suggested that this elicitor activity could be related to an interaction of rhamnolipids with the lipid bilayer of the plant plasma membrane (PPM) and lead to its destabilization, which can activate the plant defense signaling pathways. In this context, interactions of two rhamnolipids (Rha-C10-C10 and Rha-Rha-C10-C10) with membrane models and lipidic constituents of the PPM were investigated using in silico approaches. Most probable chemical structures of the rhamnolipids were determined using the STRUCTURE TREE procedure according to the molecule potential energy. The ability of these rhamnolipid structures to insert within the PPM was assessed using IMPALA simulations. IMPALA uses a membrane model in which phospholipids molecules are implicitly modeled by an empirical function and the membrane properties are modeled by energetic restraints. The ability of each rhamnolipid structure to form an assembly with several PPM constituents (phospholipid (PLPC), sterols (Sitosterol, Stigmasterol, Campesterol) and sphingolipids (GIPC, Glucosylceramide)) was calculated using the HYPERMATRIX procedure, which calculate and minimize the energies of interaction between all molecules of the complex until the lowest energy structure is reached. [less ▲]

The various experiments to be held prior to elicitor screening are detailed, along with the screening metholodogy. Explanation is given on the increasing interests of plant elicitors, or "stimulators of ... [more ▼]

The various experiments to be held prior to elicitor screening are detailed, along with the screening metholodogy. Explanation is given on the increasing interests of plant elicitors, or "stimulators of natural defenses", for the sustainability of our agro-ecosystems. [less ▲]

Elicitors are plant immunity-triggering compounds which are currently considered as one of the most promising tools in agriculture for the induction of plant resistance to various diseases (Mejía-Teniente ... [more ▼]

Elicitors are plant immunity-triggering compounds which are currently considered as one of the most promising tools in agriculture for the induction of plant resistance to various diseases (Mejía-Teniente et al., 2010). By contributing to both economic and environmental performances of agroecosystems, they can help reducing the use of chemical inputs. Although some elicitor products are already available on the market, it appears that a variable efficiency in the field, along with an uneasy integration in the current legislation and agricultural strategies, make these tools difficult to use (Walters, Ratsep, & Havis, 2013). Besides these limitations, few elicitor treatments have yet been efficiently and specifically designed to protect crop plants such as wheat, which is grown and consumed worldwide, against major diseases threatening both their yield and quality. There is a strong need to better understand the mechanisms of induced resistance in plants and develop elicitor use in agriculture. A phD research is currently led in Gembloux Agro Bio-Tech to develop a method based on eliciting agents, tested in greenhouse and field conditions, to protect winter wheat against major diseases, namely Septoria tritici, Fusarium graminearum and Fusarium culmorum. This project focuses on the screening of a large number of elicitors from different origins and structures. In 2014, we focused the first screening experiments on the protection of wheat against Septoria tritici Blotch (STB). Two winter wheat genotypes were tested: susceptible ‘Avatar’ and semi-resistant ‘Sy Epson’. Plants at 3-leaf stage were first sprayed till runoff with different concentrations of elicitors, and then inoculated 5 days later with a Septoria tritici spore suspension (106 spores mL-1) using a hand sprayer. Control plants were treated, prior to disease inoculation, with sterile water (negative control) or with BION® (ASM, Syngenta Europe; positive control). The disease severity and incidence were scored every 2 days for 28 days post-inoculation (d.p.i) by measuring the percentage of area covered with lesions and bearing pycnidia on the third leaf. The first results of these tests should enable a first discrimination of elicitors considering their dose-efficiency to reduce disease severity. After further screening of all the elicitors in hand, a determination of the elicitation pathways of the most efficient molecules tested will be undertaken. We intend to study the influence of various factors (i.e Temperature, relative humidity, plant development stage) on the elicitation potential and develop a formulation to be finally tested under field conditions. [less ▲]

Model membrane based on phospholipids (PL) layers are useful to mimic properties of plasma membranes. The interactions between new synthesized phenolic glycolipids (PGL) and biological membrane are ... [more ▼]

Model membrane based on phospholipids (PL) layers are useful to mimic properties of plasma membranes. The interactions between new synthesized phenolic glycolipids (PGL) and biological membrane are crucial to determine their potential as drug candidates and their cytotoxicity . [less ▲]

Crop plants are constantly exposed to a wide range of environmental stresses that can cause major productivity loss. Fungicide treatments are the most efficient disease control methods used up to now ... [more ▼]

Crop plants are constantly exposed to a wide range of environmental stresses that can cause major productivity loss. Fungicide treatments are the most efficient disease control methods used up to now. However, the environmental and health issues caused by these chemicals make it urgent to develop safer methods for pathogen control. In the optic of a sustainable agriculture, several biocontrol tools have been developed during the last decades. Elicitors are increasingly subject to research as interesting alternatives to phytosanitary products. Yet, few efficient formulations exist on the market, and no product has been designed specifically to protect wheat crops. This study will thus focus on the the manipulation of host natural defenses through the use of elicitors as a preventive treatment against major wheat diseases such as Septoria tritici, Fusarium graminearum and Fusarium culmorum. [less ▲]

The use of chemical pesticides causes problems for human health and environment. In this context, there is an increasing interest for alternative products such as biopesticides. Among them, elicitors act ... [more ▼]

The use of chemical pesticides causes problems for human health and environment. In this context, there is an increasing interest for alternative products such as biopesticides. Among them, elicitors act on the plants by inducing systemic resistance against diseases caused by fungal, viral, bacterial agents and insects. The target of the elicitors is supposed to be the plant plasma membranes (PPM). The main mechanisms of interaction of many elicitors involve proteic receptors but lipid-based elicitors (LBE) may preferably interact with the lipidic fractions of PPM. However there is no detailed information at the molecular level on the PPM-LBE interactions. Our work is focused on a original synthetic LBE composed of a mannoside linked to a myristic acid. It has potential elicitor activities as shown by the assays on tobacco root cells. These activities could be related to its interaction with the lipidic phase of PPM. Since PPM are complex entities, the analyses of the PPM- molecule interactions are quite difficult. In this context, these interactions were carried out using biomimetic membranes of PPM such as Langmuir monolayers and multilayers. The effects of our molecule on these membranar systems were investigated by biophysical and in silico approaches. [less ▲]

Nowadays, many health and environmental problems are caused by the use of chemical pesticides. In this context, an increasing demand for alternative products such as biopesticides has been observed. Among ... [more ▼]

Nowadays, many health and environmental problems are caused by the use of chemical pesticides. In this context, an increasing demand for alternative products such as biopesticides has been observed. Among biopesticides, elicitor molecules which are able to trigger immune defense responses in plants are one of the most promising options. Although numerous elicitors have been discovered, the mechanisms involved in the perception, by plants, of only a few molecules have been identified. These elicitors usually interact with proteic receptors but we have recently shown that they may also act on the lipid phase of the plasma membrane. This project first aims to improve our understanding of the molecular mechanisms involved in the recognition of specific lipid based elicitors (LBE). On that basis, the FIELD project will contribute to the design and the development of innovative compounds derived natural LBE. A multi-disciplinary approach, based on chemistry, bio-physics, bio-chemistry, and phytopathology will be followed by a consortium of different research groups from Gembloux Agro-Bio Tech in close collaboration with teams from foreign institutions. [less ▲]